Alternative PHP Cache, or APC, is a module for Apache servers that is used to cache the output code of script apps. It is very useful for scripts with large source code and can speed up such a website up to 3 times. PHP sites are dynamic and any time a visitor opens some page, the script connects to a database in order to retrieve some content, and then the code is parsed and compiled prior to it being shown to the visitor. If the output code doesn't change however, that's the case with websites that display the same content at all times, such actions trigger unnecessary reading and writing. What APC does is that it caches the already compiled program code and delivers it every time visitors browse a website, so the database does not need to be accessed and the code doesn't need to be parsed and compiled continuously, which in turn lowers the website loading time. The module can be pretty effective for informational Internet sites, blogs, portfolios, and many others.